U.S. patent number 4,162,486 [Application Number 05/757,632] was granted by the patent office on 1979-07-24 for encoded electrical control systems.
This patent grant is currently assigned to TRE Corporation. Invention is credited to Leopold S. Wyler.
United States Patent |
4,162,486 |
Wyler |
July 24, 1979 |
Encoded electrical control systems
Abstract
Encoded electrical control systems for household applications
each employ an encoder/transmitter that provides an encoded signal
and a receiver/decoder which effectuates control of an associated
device only upon receipt of a signal containing the code unique to
that specific receiver/decoder. For household applications, a
separate receiver/decoder, each having its own recognition code, is
associated with each power outlet or electrical device to be
controlled. A common controller includes an encoder/transmitter and
a control switch for each device, along with means such as an rf
carrier source and modulator, for transmitting all the
encoder/transmitter outputs over the electrical distribution
system. When a particular switch is actuated, the associated
encoder/transmitter sends a signal containing the code of the
corresponding receiver/decoder, which in turn effectuates the
intended control function.
Inventors: |
Wyler; Leopold S. (Beverly
Hills, CA) |
Assignee: |
TRE Corporation (Beverly Hills,
CA)
|
Family
ID: |
27098152 |
Appl.
No.: |
05/757,632 |
Filed: |
January 7, 1977 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
660686 |
Feb 23, 1976 |
4141332 |
|
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Current U.S.
Class: |
340/12.15;
307/40; 340/870.22; 307/31; 340/870.24; 340/310.18; 340/12.5 |
Current CPC
Class: |
F02P
11/04 (20130101); H04L 12/2803 (20130101); H04L
12/282 (20130101); G05B 19/0423 (20130101); B60R
16/0315 (20130101); G05B 2219/2642 (20130101); G05B
2219/21071 (20130101); G05B 2219/25188 (20130101) |
Current International
Class: |
G05B
19/042 (20060101); F02P 11/04 (20060101); H02J
13/00 (20060101); G05B 19/04 (20060101); F02P
11/00 (20060101); H04L 12/28 (20060101); B60R
16/02 (20060101); H04M 011/04 () |
Field of
Search: |
;340/31A,31CP,206,151,152R ;307/1R,252B,31,32,40 ;315/159,82,291
;343/225 ;364/492 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Caldwell, Sr.; John W.
Assistant Examiner: Crosland; Donnie L.
Attorney, Agent or Firm: Spensley, Horn, Jubas &
Lubitz
Parent Case Text
This is a division of application Ser. No. 660,686, filed Feb. 23,
1976, now U.S. Pat. No. 4,141,332.
Claims
Intending to claim all novel, useful and unobvious features shown
or described, the applicant claims:
1. An electrical control system for remote control of devices
powered from a common electrical distribution system,
comprising:
a controller containing one or more switches and associated
encoder/transmitters each providing a different unique, encoded
signal in response to actuation of a respective switch,
transmission means for transmitting the encoded signals from said
encoder/transmitters over said electrical distribution system,
and
respective receiver/decoder means associated with each device to be
controlled, each receiver/decoder means being connected to receive
the encoded signals transmitted over said distribution system and
to effectuate control of said respective device in response to
receipt only of the unique code associated with that specific
receiver/decoder means, and wherein in addition to said encoded
signal said encoder/transmitter also transmits a plurality of data
bits that specify the condition of the associated switch, and
wherein each receiver/decoder means further includes means,
responsive to receipt of said plurality of data bits, for modifying
the control effectuated by said receiver/decoder means in response
to the contents of said data bits, and wherein:
said plurality of data bits indicate the setting of a control
member in said controller, and wherein:
said receiver/decoder means effectuates proportional control of the
associated device in response to the contents of said data
bits.
2. An encoded electrical control system for remote control of
devices powered from a common electrical distribution system,
comprising:
a controller including a switch and a control member, and an
associated encoder/transmitter providing a unique, encoded signal
in response to actuation of said switch, said encoder/transmitter
providing said encoded signal repetitively at a repetition rate
determined by the setting of said control member,
transmission means for transmitting the encoded signals from said
encoder/transmitter over said electrical distribution system,
and
respective receiver/decoder means associated with each device to be
controlled, each receiver/decoder means being connected to receive
the encoded signals transmitted over said distribution system and
to effectuate control of said respective device in response to
receipt only of the unique code associated with that specific
receiver/decoder means, and wherein the associated receiver/decoder
means effectuates control of the associated device in proportion to
the repetition rate of said encoded signal.
3. An encoded electrical control system according to claim 2
wherein said encoder/transmitter comprises:
a memory (148) for storing a unique code of N bits,
access means (146, 147) for accessing said code from said memory
repetitively in bit serial format, at a read-out rate established
by the setting of said control member (85b), wherein said
transmission means comprises:
a RF signal source (115) and a modulator (110), connected to said
memory and to said source, for modulating the RF signal from said
source with the bit serial code that is repetitively accessed from
said memory, and wherein said receiver/decoder means comprises:
a detector (125') and a demodulator (127') for recovering said
repetitive serial format data from said RF signal,
comparator means (151, 153, 154) for comparing the code represented
by said recovered serial format data with a stored recognition code
uniquely associated with that specific receiver/decoder means, and
said comparator producing an output signal each time that equality
is detected, said output signals thus occurring at a repetition
rate corresponding to the repetitive access rate of said access
means,
integrator means (156), receiving said output signals from said
comparator means, for producing a control signal proportional to
the repetition rate thereof, said control signal thereby being
proportional to the setting of said control member, and
utilization means (71, 75a) controlled by said proportional control
signal.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to encoded remote electrical control
systems, and partcularly and to systems for the remote control of
power outlets, light fixtures and other devices on a common
electrical distribution system.
2. Description of the Prior Art
In a conventional motor vehicle ignition system, a key operated
lock is used to actuate the ignition switch. Closure of the switch
connects battery power to essential ignition system components such
as the ignition coil and the distributor. In the "start" position,
battery power also is supplied to the engine's starter. The
security of such an ignition system depends on the integrity of the
lock, and the degree to which the mechanical installation can
prevent tampering or "hot-wiring".
A major weakness in conventional ignition systems is that the wire
carrying power from the battery to the ignition coil goes by way of
the ignition switch. Direct shorting of the switch contacts is all
that is required to start and run the engine. Alternatively, the
battery can be directly hot-wired to the ignition system components
under the hood. Security is poor.
In the past, the usual approach to improving security has been to
enclose the critical interconnections and components in rigid
housings. At least one automobile manufacturer locates the ignition
coil on the fire wall between the engine and the dashboard, and
provides a unitary armored cable from the ignition coil housing to
the key switch assembly. Since power must be supplied to the
ignition coil to start the engine, "hot-wiring" can only be
accomplished by physically destroying the armored cable assembly.
While this can be done with the appropriate tools, it is
sufficiently difficult so as to discourage a would-be thief who is
anxious to accomplish the job quickly.
The difficulty with this prior art approach is that the cost of
such armored assemblies is high, and their use complicates normal
maintenance. For example, in the system just described if a wire
within the ignition coil should break, the entire armored cable
assembly must be taken out to permit removal and disassembly of the
ignition coil. Replacement ignition coils are only sold as a unit
with the armored cable attached.
An object of the present invention is to provide a secure ignition
system for a motor vehicle which does not depend on extensive
mechanical armoring to prevent theft or "hot-wiring". Another
object is to provide a secure ignition system which utilizes an
electrical code transmission device, preferably an integrated
circuit chip contained in the ignition switch assembly, to transmit
an encoded signal to a receiver/decoder associated with the
essential ignition system components. Receipt of this signal causes
the receiver/decoder to effectuate a necessary electrical
connection to the ignition system component, thereby enabling
engine operation.
"Hot-wiring" at the ignition switch is prevented since shorting of
the leads to the switch and transmitter assembly will not cause
transmission of the necessary code, and hence will not result in
engine ignition. By enclosing the receiver/decoder and the
circuitry used to effectuate the necessary ignition system
connection in a small tamperproof housing, "hot-wiring" at the
ignition coil or distributor likewise is prevented. The inventive
system may be used in conjunction with a pushbutton type electronic
combination lock in place of a key-operated lock.
The inventive encoded control systems also are useful for remote
control of power outlets, lighting fixtures and other devices in a
building electrical system. In a conventional household or office
electrical installation, the switches normally are mounted in the
walls and permanently wired to associated light fixtures, outlets,
and other electrical appliances. Such systems afford little or no
flexibility. For example, switches to control overhead lights
usually are mounted on the wall next to a door. This is convenient
to turn on the lights when entering the room, but may be
inconvenient otherwise. For example, in a bedroom it necessitates
getting out of bed to turn off the light.
Some flexibility is afforded by providing a pair of single-pole,
double-throw switches in separate locations to control the same
light or outlet. Typically this is done in a stairway, with
switches located at the top and bottom of the stairs. But even with
this arrangement, the switch locations are fixed and cannot be
moved without major rewiring and structural relocation of the
switches in the walls.
A further object of the present invention is to provide an
electrical control system in which the switch location is
completely flexible. The switches, dimmers and the like are not
wall mounted, but are situated in a portable controller or switch
box which may be moved to any desired location. Each controlled
light fixture, outlet or other device has associated with it a
control circuit that responds to an encoded signal transmitted from
the controller via the electrical distribution system. When a
controller switch is actuated, the transmitted signal is recognized
only by the intended control circuit, and effectuates turn-on,
turn-off, dimming or other control of the associated electrical
device.
With this arrangement, the controller may be plugged into any
outlet in the common electrical distribution system. When furniture
is moved, the controller also can be moved. Thus in a bedroom, if
the bed is relocated, the light switches readily can be positioned
next to the new bed location. Alternatively, the controller may be
moved from one room to another to remotely control the lights in
either of these, or yet another room.
SUMMARY OF THE INVENTION
These and other objectives are acheived by providing electrical
control systems in which actuation of a switch or other control
member causes an encoder/transmitter to generate a unique, encoded
signal. At the controlled device, this signal is processed by a
receiver/decoder that compares the signal code to a "recognition"
code unique to the specific receiver. If the codes are identical, a
power switch or other control circuit is enabled so as to
effectuate the intended control function.
In motor vehicle applications, a secure ignition system is acheived
by locating the encoder/transmitter in the key switch assembly
housing, and by locating the receiver/decoder adjacent an essential
ignition system component. When the ignition switch is closed, a
unique code is transmitted which causes the receiver/decoder to
effectuate a necessary electrical connection to that ignition
system component. Security is acheived since (a) the shorting of
the wires to the ignition switch and transmitter assembly will not
cause transmission of the necessary code, (b) effectuating the
necessary electrical connection cannot be accomplished without
tampering with the receiver/decoder housing, and (c) insertion of a
signal onto the line, as from a random signal generator, will not
actuate the receiver/decoder without specific knowledge of the code
that is unique to this particular motor vehicle.
In household and other building applications, the receiver/decoder
associated with each controlled outlet, lighting fixture or the
like has its own unique recognition code. In the controller, each
separate switch, dimmer or other control member causes an
associated encoder/transmitter to generate a code corresponding to
that unique recognition code of the device to be controlled. This
code is transmitted over the electrical distribution system to all
of the receiver/decoders, but is recognized only by the one
associated with the device being controlled.
Advantageously the encoded signals from the controller are
transmitted in such a manner that the controller may be moved from
place to place. For example, the controller may contain an rf
carrier source and means for modulating that carrier with the
encoded signals. The resultant modulated rf carrier then may be
capacitively coupled to the electrical distribution system via a
line and plug from the controller itself. With this arrangement,
the controller can be moved from place to place and merely plugged
into the nearest electrical outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the invention will be made with reference
to the accompanying drawings wherein like numberals designate
corresponding parts in the several figures.
FIGS. 1 and 1A are pictorial views of the inventive secure ignition
system for a motor vehicle.
FIG. 2 is an electrical block diagram of the secure ignition system
of FIG. 1, showing both the encoder/transmitter and
receiver/decoder components.
FIG. 3 is a pictorial view of a typical installation of the
inventive household encoded electrical control system.
FIG. 4 is an electrical block diagram of the controller and
associated encoder/transmitter circuitry used in the household
electrical control system of FIG. 3.
FIG. 5 is an electrical block diagram of the receiver/decoder and
load control switch components of the household electrical control
system of FIG. 3.
FIGS. 6 and 7 are electrical block diagrams of alternative
encoder/transmitter and receiver/decoder circuitry for providing
remote dimming control in an encoded household electrical control
system like that of FIG. 3.
FIG. 8 is an electrical block diagram of an alternative embodiment
of the secure ignition system of FIG. 1, utilizing code selection
switches for code entry or transmission actuation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following detailed description is of the best presently
contemplated modes of carrying out the invention. This description
is not to be taken in a limiting sense, but is made merely for the
purpose of illustrating the general principles of the invention
since the scope of the invention best is defined by the appended
claims.
Operational characteristics attributed to forms of the invention
first described also shall be attributed to forms later described,
unless such characteristics obviously are inapplicable or unless
specific exception is made.
In FIG. 1, the inventive secure motor vehicle ignition system 10 is
installed in an automobile 11. The key-operated ignition switch
assembly 12 (FIG. 1A) is mounted on the dashboard 13 by means of a
nut 14. The assembly 12 includes a conventional tumbler lock 15
which, when rotated by a key 16, closes a switch 17 contained
within a tamperproof housing 18 that is an integral part of the
assembly 12.
Unlike a conventional ignition system, the key-switch 17 does not
directly connect power from the automobile battery 19 to the engine
electrical components such as the ignition coil 20 and the
distributor 21. Rather, in accorandance with the present invention,
the switch 17 actuates an encoder/transmitter 23 contained within
the housing 18. This device 23 transmits a unique code via a line
24 to a receiver/decoder 25 contained in a rigid housing 26 that is
mounted to the vehicle engine 27. Upon receipt of the correctly
encoded signal from the transmitter 23, the receiver/decoder 25
actuates a power switch 28, also contained in the housing 26, to
connect electrical power from the battery 19 to the ignition coil
20. The coil 20 itself is mounted on the tamperproof housing
26.
From the driver's point of view, operation of the inventive
ignition system 10 is exactly as in a conventional automobile. That
is, when the key 16 is turned, power is connected to the ignition
coil 20 and the engine operates normally. From a security point of
view, however, the operation is quite different. First, hot wiring
of the ignition switch assembly is impossible. To short out the
switch 17 would require physical entry into the housing 18, which
preferably is sufficiently solid so as to prevent such tampering.
If the wire 29 leading from the battery 19 to the housing 18 is
shorted to the wire 24, electrical actuation will not result. This
will merely apply a continuous dc voltage to the input of the
receiver/decoder 25, and that device will not actuate the power
switch 28 in the absence of the proper encoded signal. Preferably,
the housing 26 itself is sufficiently rigid so as to prevent
tampering or "hot-wiring" of the power switch 28. In other words,
there is no way of connecting the battery 19 to the primary of the
ignition coil 20 except by forcibly breaking into the housing 26
and shorting out the power switch 28.
A would-be thief of some technical bent may try to actuate the
receiver/decoder 25 by connecting a signal generator to the line 24
so as to simulate the encoder/transmitter 23. However, even if the
data format on the line 24 were known, the thief would not know the
specific code that is produced by the encoder/transmitter 23, since
advantageously that code is unique to each vehicle 11. If the wrong
code is received by the decoder 25, the power switch 28 will not be
actuated. Furthermore, if the code is of sufficient length (i.e.,
number of binary bits), then even if a random binary number
generator were connected to the line 24, the probability of
generating the specific code for this vehicle 11 is extremely low.
In this manner, high security is acheived.
Typical circuitry for the encoder/transmitter 23 and for the
receiver/decoder 25 is shown in FIG. 2. However, the invention is
by no means limited to this particular circuitry embodiment, and
any alternative means for producing an encoded signal may be used
as the transmitter 23 in conjunction with any corresponding decoder
circuitry in the receiver 25. Advantageously, but not necessarily,
the encoder/transmitter 23 may be implemented using an integrated
circuit chip of small size, so that the housing 18 need be no
larger than the switch housings currently in use. Similarly, the
receiver/decoder 25 may be implemented using integrated circuit
technology.
In the embodiment of FIG. 2, the code is stored in a read only
memory 31, and preferably consists of N binary bits. For example,
this code may be "1 0 0 1 1 0". Advantageously, each bit of the
code is stored in a single storage location of the memory 31 and is
accessed therefrom as the address of the corresponding location is
provided to the memory 31 on a line 32 from a counter 33.
When the key switch 17 is closed, battery power is supplied to the
memory 31, to the counter 33 and to a clock 34 via a line 29a.
Clock pulses are supplied via a line 35 to increment the counter
33. In turn, the counter output on the line 32 sequentially
accesses the stored code from the memory 31 and provides this code
36' on a line 36.
The code is converted to a bi-level format for transmission on the
line 24 by circuitry including a voltage divider consisting of the
resistors 37, 38 and a pair of gates 39, 40. When a binary "1" is
present on the line 36 concurrently with a clock pulse 35', an
AND-gate 41 enables the gate 39 to supply a +12 volt signal from
the line 29a via a diode 42 to the line 24. When a binary "0" is
present on the line 36, a lower level signal of say +4 volts is
provided to the line 24. The voltage divider 37, 38 supplies a
constant +4 volt signal to the gate 40. The low or binary "0"
signal on the line 36 provides a high output from an inverter 43
that provides one input to an AND-gate 44 which is enabled by the
clock pulses 35'. The resultant output from the AND-gate 44 enables
the gate 40 to supply the +4 level via a diode 45 to the line 24
each time a binary "0" is read from the memory 31. The resultant
bi-level encoded signal present on the line 24 is illustrated by
the wave shape 24' in FIG. 2. This signal format has the advantage
of permitting easy recovery of the clock pulses at the receiver 25,
and thus simplifies synchronization in the system.
In the receiver 25, a level detector 47 provides a high output on a
line 48 whenever a +12 volt signal is detected on the line 24
indicating the presence of a binary "1". Similarly, the detector 47
provides a high signal on a line 49 whenever a +4 volt signal is
detected indicating a binary "0". By combining these signals on the
lines 48 and 49 in an OR-gate 50, a clock pulse train 35a is
recovered on a line 51 that is exactly synchronous with the clock
pulses 35' from the clock 34. These pulses 35a are used to shift a
shift register 52 that receives the incoming data stream from the
line 48. As indicated by the wave shape 36a, this data stream
corresponds to the code 36' read out of the memory 31.
A code identical to that contained in the read only memory 31 is
stored in a register 53. This recognition is compared with the
contents of the shift register 52 by a comparator 54. If the
correct code is received from the line 24, the comparator 54 will
provide a high signal on a line 55 that sets a flip flop 56 to the
"1" state. As a result, an enable signal will be provided from the
flip flop "1" output via a line 57 to turn on the power switch 28.
This will connect power from the battery 19 to the ignition coil 20
and to the distributor 21. Of course, if an incorrect code is
received, no output will be provided from the comparator 54, the
flip flop will remain in the "0" state, and the power switch 28
will remain off.
Note that in the embodiment of FIG. 2, power is supplied to the
memory 31, the counter 33 and the clock 34 for as long as the key
switch 17 remains closed. Therefore, since the counter 33 if of
module N and hence recycles repetitively, the code signal 24' will
be transmitted down the line 24 for as long as the switch 17
remains closed. As a result, in the receiver 25, the comparator 54
will produce a sequential set of pulses on the line 55. These
pulses will occur once for each complete transmission of the code
for as long as the key switch 17 is actuated. A timing circuit 59
is used to reset the flip flop 56, and thereby turn off the power
switch 28, after the last transmission of the code from the
transmitter 23.
To this end, the circuit 59 includes a clock 60 and a counter 61
that cooperate to produce a reset pulse on a line 62 after a time
duration slightly greater than that required to transmit the entire
stored code. The counter 61 is reset by occurence of the pulse on
the line 55. Therefore, if the code 24' were transmitted only once,
the single resultant pulse on the line 55 would set the flip flop
56 to the "1" state and also reset the counter 61 to zero. A short
time later, the output from the counter 61 will reset the flip flop
56 to the "0" state thereby terminating the signal on the line 57
and turning off the power switch 28. However, if the code 24a is
transmitted once again before the counter 61 provides the output
pulse on the line 62, the resultant signal on the line 55 will
reset the counter 61 and start a new time period. As a result, the
flip flop 56 will remain set to "1" and the power switch 28 will
remain on. With this arrangement, the switch 28 in fact will remain
on as long as the key switch 17 is held closed. Shortly after the
switch 17 is opened, the power switch 28 will turn off.
The ignition switch assembly 12 also can be used to control the
engine starter. In one implementation (not shown), the switch 17
may have a second set of contacts that enable another
encoder/transmitter (not shown) identical to the device 23 and also
contained in the housing 18. The output from that transmitter then
may be supplied via another line like the line 24 to another
receiver/decoder identical to the receiver 25. That receiver may be
used to control another power switch, analogous to the switch 28,
that connects battery power to the engine starter.
An alternative implementation is shown in FIG. 2. Therein, the
encoder/transmitter 23 stores a second code in the memory 31 which
is selectively accessed when the starter switch contacts 63 of the
switch assembly 12 are closed. This provides power to the clock 34,
counter 33 and memory 31 via a line 29b, a diode 64 and the line
29a. The signal on the line 29b also conditions the memory 31 for
readout of the starter-indicating code.
The receiver/decoder 25 has a second storage register 65 containing
the corresponding starter recognition code, together with a second
comparator 66 for comparing that code with the contents of the
shift register 52. When the second "starter" code is present, the
resultant high output signal from the comparator 66 present on a
line 67, actuates a starter switch 68 which then connects power
from the battery 19 to the starter 69.
Although not illustrated, time-based codes could be employed in
connection with the present invention. For example, the
encoder/transmitter 23 could generate a unique code consisting of a
sequence of pulses of different, controlled time duration. A quartz
crystal-controlled oscillator, not unlike that employed in a
digital electronic watch, could be used as the time standard,
together with appropriate circuitry for generating the time-based
code. A similar time standard and comparison circuitry could be
used in the receiver/decoder 25 to recognize the specific
time-encoded signal and provide the control signal to the power
switch 28.
The household application of an encoded electrical control system
is illustrated in FIG. 3. Referring thereto, a typical room 70 may
have a chandelier 71, two or more electrical outlets 72, 73 and
other electrical appliances such as a mechanized drapery opener 74.
In accordance with the present invention, each of the fixtures 71,
74 and outlets 72, 73 is provided with a respective
receiver/decoder 75-78 and associated electronic switch 75a-78a. A
single, portable controller 80 provides individual remote control
for each of the fixtures 71, 74 and outlets 72, 73. The controller
80 may be moved to any desirable location, and can be plugged into
either outlet 72 or 73, or into a like outlet in another room that
is connected to the same electrical distribution system as the room
70.
In the embodiment of FIG. 3, the controller 80 has three control
switches 82, 83, 84 intended respectively to control the outlets
72, 73 and the drapery mechanism 74. In addition, it has a dimmer
knob 85 intended for remote control of the chandelier 71.
Associated with each of the controls 82-85 is a respective
encoder/transmitter 86-89 each storing a unique code corresponding
to the like code contained in the respective receivers 76, 77, 78
and 75. When e.g. the switch 83 is closed, the transmitter 87
modulates an rf carrier that is transmitted via the room electrical
distribution system to all the receivers 75-78. However, the unique
transmitted code corresponds only to that of the receiver 77, so
that only the switch 77a is actuated. As a result, ac power is
supplied to the outlet 73, thereby turning on any appliance (such
as the lamp 90) that is plugged into that outlet. Similarly, if the
dimmer knob 85 is rotated, the corresponding transmitter 89 sends
out a uniquely coded signal that is recognized only by the receiver
75. This alters the duty cycle of the associated switch 75a so as
to change the light intensity from the chandelier 71.
Illustrative circuitry for the controller 80 is shown in FIG. 4.
Three identical encoder/transmitters 86-88 are employed, differing
only in that each stores a different code. When the switch 83 is
closed, voltage from a battery 93 triggers a monostable
multivibrator ("one-shot") 94 that produces a pulse on a line 95
which triggers a flip flop 96 to the "1" state. As a result, a high
signal is provided on an output line 97 which designates that the
switch 83 is "on". The pulse on the line 95 also is supplied via an
OR-gate 98 to the set input of a flip flop 99. The resultant high
"1" output of the flip flop 99 enables a gate 100 to feed clock
pulses from a clock 101 to a counter 102 of modulo (N+1). The
resultant incrementing of the counter 102 causes read out of the
code stored in a read only memory 103.
The first clock pulse to reach the counter 102 sets the contents to
1 (base 10). A resultant counter 102 output on a line 105 enables
an AND-gate 106 to pass the signal from the line 97 via an OR-gate
107 to an output line 108. This high signal, which is handled as an
extra bit transmitted prior to the code, indicates that the switch
83 is closed.
Subsequent pulses from the clock 101 increment the counter 102 to
counts of 2 through (N+1). At each such count, the corresponding
code bit is read from the memory 103 and supplied via the OR-gate
107 to the line 108. In this manner, the "on/off bit" and the code
from the encoder 87 are transmitted via the line 108 to a modulator
110 that is common to all of the encoder/transmitters 86-88 in the
controller 80.
At the next, (N+2).sup.th pulse from the clock 101, the counter 102
will reset to zero and will provide a reset pulse on a line 111.
This pulse is slightly delayed in a delay circuit 112 and supplied
to the reset input of the flip flop 99. This causes the flip flop
99 to go to the "0" state, thereby disabling the gate 100 and
causing the counter 102 to remain set at zero. As a result, code
transmission is inhibited. In other words, the on/off bit and the
code are transmitted only once. Alternatively, the pulse from the
line 111 may be used to increment an optional counter 113 that
controls how many times the code is transmitted. For example, it
may be desireable to transmit the code two or three times to insure
correct reception and decoding in the event that noise on the
electrical distribution lines interferes with correct decoding of
the code when transmitted the first time. In this instance, when
the counter 113 reaches a count equal to the desired number of
transmissions of the code, an output signal is provided to reset
the flip flop 99.
The controller 80 is provided with an rf source 115 that provides
an rf carrier on a line 116. This carrier is modulated by the
on/off bit and the code from the transmitter 87 by the modulator
110. The resultant modulated rf signal is transmitted via a
capacitor 117 and a line 118 to a plug 119 that can be inserted
into any electrical outlet in the room 70 or any nearby room.
A typical receiver/decoder 77 is shown in FIG. 5. Advantageously
the receiver 77 and its associated electronic switch 77a are
mounted in a common housing 121 (FIG. 3) adjacent the associated ac
outlet 73. The power lines 122a, 122b from the power distribution
box supplying the room 70 terminate at the electronic switch 77
which in turn is connected to the outlet 73 by means of lines 123a,
123b. The switch 77a may comprise a relay or any electronic switch,
known per se, employing a silicon controlled rectifier (SCR) or
other semiconductor switching device. The switch 77a is actuated in
response to a high control signal on a line 124 that is provided
when the receiver 77 detects the code transmitted from the
encoder/transmitter 87.
To this end, the receiver 77 includes a conventional rf detector
125 that is connected to the power lines 122a, 122b by capacitors
126a, 126b. The detector is tuned to the frequency of the rf source
115. The detector output is supplied to a demodulator 127 that
recovers the data from the detected rf signal. Of course, the
demodulator 127 is of the same character of the modulator 110. For
example, if the modulator 110 accomplishes frequency shift keying
of the carrier on the line 116, the demodulator 127 responds to
such frequency shift keyed signal and provides on a line 128 a data
signal corresponding to that supplied on the line 108 in the
transmitter 87. This signal is supplied to the data input of a
shift register 129 that is shifted by clock pulses from a clock 130
which operates in synchronism with the clock 101.
After receipt of (N+1) bits, the "on/off bit" will be contained in
the last shift register position 129a and the received code will be
contained in the remaining positions of the shift register 129.
This code is compared with the recognition code of the receiver 77
that is stored in a register 131 by a comparator 132. If the codes
are identical, meaning that the signal is intended for this
receiver 77, the comparator 132 provides a high output on a line
133 that enables an AND-gate 134. As a result, the "on/off bit"
contained in the shift register position 129a is supplied via the
AND-gate 134 to the set input of a flip flop 135. The "1" output of
the flip flop 135 thus comprises an on/off signal on the line 124
that is high if the received "on/off bit" itself is high. This
signal on the line 124 actuates the electronic switch 77 to turn on
power to the outlet 73. In this manner, closure of the switch 83 in
the controller 80 accomplishes remote turn-on of the outlet 73. Of
course, the modulated rf signal transmitted by the controller 80
also is received by the other receivers 75, 76 and 78. However, the
transmitted code is not the same as the recognition code stored in
those respective receivers, so that no control function is
accomplished therein.
When the switch 83 is opened, the output on an inverter 137 (FIG.
4) triggers a monostable multivibrator 138 which resets the flip
flop 96 to the "0" state so that the on/off signal on the line 97
goes low. The output from the "one-shot" 138 also is supplied via
the OR-gate 98 to the set input of the flip flop 99. This initiates
another transmission cycle during which the "on/off bit" and the
code stored in the memory 103 are transmitted via the line 108 to
the modulator 110. In this instance, however, the "on/off bit" is
low (binary "0").
When this signal is received at the receiver/decoder 77, the shift
register location 129a will store a "0" bit so that the output of
an inverter 139 will be high. In this instance, the high comparator
output on the line 133 will enable an AND-gate 140 that supplies
the output of the inverter 139 to the reset input of the flip flop
135. This resets the flip flop to the "0" state causing the on/off
signal on the line 124 to go low. This causes turn off of the
electronic switch 77a so that power to the outlet 73 is shut
off.
Although not illustrated, the clocks 101 and 130 may be
synchronized to some multiple of the ac line frequency. Since the
controller 80 and the receiver 77 both are connected to a common ac
power distribution system, the ac line frequency can be used as a
common frequency reference source for these clocks.
The encoder/transmitter 89 of FIG. 6 and the associated
receiver/decoder 75 of FIG. 7 may be used to accomplish remote
dimming control of the fixture 71. Code transmission is initiated
when the dimmer knob 85 is rotated slightly so as to cause closure
of a switch 85a. The extent of dimming is controlled by a
potentiometer 85b which is ganged to the switch 85a and controlled
by the knob 85.
Closure of the switch 85a supplies a voltage from the battery 93 to
enable a gate 145 to transmit clock pulses from a voltage
controlled oscillator 146 to a counter 147. The clock pulse rate is
determined by the setting of the potentiometer 85a. The counter 147
controls read out of the stored code from a read only memory 148.
The code is supplied via the line 108 to the modulator 110
described above.
The counter 147 is of modulo N where N is the number of bits in the
code stored in the memory 148. With this arrangement, when switch
85a is closed, the code will be repetitively read from the memory
148 and transmitted to the line from the modulator 110 at a rate
that is determined by the setting of the potentiometer 85a.
At the receiver 75 the incoming rf signal is coupled via a
capacitor 126' to an rf detector 125'. The signal is demodulated by
a demodulator 127' that supplies a data output via a line 150 to a
shift register 151 of N-bit length. The register 151 is shifted in
synchronism with the incoming data rate in response to a circuit
152 which recovers a sync signal from the demodulated data.
The identifying code of the receiver 75 is stored in a register
153. The contents of the shift register 151 is compared with this
code by a comparator 154. If the incoming signal is intended for
this receiver 75, an equal comparison will result each time the
complete code is received from the transmitter 89. Thus the
comparator 154 will provide an output pulse on a line 155 each time
that the code is received. Since the rate at which the code is
received depends on the setting of the VCO clock 146, the rate at
which the comparison pulses occur on the line 155 will be
indicative of the setting of the dimmer knob 85. These pulses in
turn are integrated by an integrator 156 to provide a voltage on a
line 157 that is proportional to the pulse rate on the line 155. In
other words, the voltage on the line 157 will be proportional to
the setting of the potentiometer 85 in the transmitter 89.
Advantageously the control switch 75 which controls the power
supplied from the ac line 122' to the fixture 71 is the type which
adjusts the duty cycle of the supplied power in response to a dc
control voltage. Such circuits are known per se and often use a
ramp voltage to control the on-time or duty cycle of a silicon
controlled rectifier connected in the ac path. The voltage on the
line 157 is used to control this duty cycle. As a result, the duty
cycle of the ac signal reaching the fixture 71, and hence the
brightness of the chandelier, will be controlled remotely by the
dimmer knob.
FIG. 8 shows an alternative embodiment of the secure ignition
system for a motor vehicle, wherein an electronic combination lock
is used in place of the key-lock ignition switch, or in which the
correct code first must be entered by the driver using a set of
code selection switches 160.
In one mode of operation, the proper subset of pushbuttons 161-1
through 161-10 must be depressed in the correct order so as to
enter the correct code into a shift register 162. This correct code
then is transmitted to the receiver/decoder 25 (FIG. 2) to actuate
the engine as described above. The presence of the correct code in
the register 162 is ascertained by a comparator 163 which compares
these contents with a recognition code contained in a storage
register 164. In embodiments wherein the contents of the shift
register 162 is transmitted to the receiver/decoder 25, the
recognition code stored in the register 164 will be the same as
that stored in the register 53 of the receiver/decoder 25.
Upon determination that the correct code has been entered via the
selection switches 160, the comparator 163 will provide a high
output on a line 165 to set a flip flop 166 to the "1" state. The
resultant high signal on a line 167 will enable an AND-gate 168 to
transmit clock pulses from a clock 34' to the shift input 169 of
the register 162. This will cause the code stored therein to be
read out serially onto the line 36. From there the code is
converted to bi-level format by the circuitry shown in FIG. 2 for
transmission to the receiver/decoder 25.
Code transmission is terminated by resetting the flip flop 166, and
thereby disabling the AND-gate 168, after the code has been read
out of the shift register 162. To this end, the clock pulses fed to
the shift input 169 also are supplied to a counter 170. When the
counter 170 reaches a count equal to the number of bits in the code
stored in the shift register 162, an output is provided on a line
171 to reset the flip flop 166 and thereby terminate code
transmission.
Illustrative circuitry 175 indicates the manner in which the
switches 160-1 through 160-10 may be connected for code selection
and entry into the shift register 162. In the typical embodiment
shown, the pushbuttons 161-4, 161-2 and 161-7 must be depressed in
that order to enter the correct code. In this embodiment, the
correct code than has a binary "1" in each of shift register
positions 162-2, 162-4 and 162-7, and has a binary "0" in each of
the other shift register 162 positions.
If the correct pushbutton 161-4 first is depressed, the switch
160-4 is closed so as to connect a voltage from a battery 176 via a
line 177 to the register storage position 162-4, thereby causing a
binary "1" to be entered into this location. The signal on the line
177 also sets a flip flop 178 to the "1" state so as to enable an
AND-gate 179. If the correct pushbutton 162-2 next is depressed,
the AND-gate 179 receives a second input and thus provides a high
output on a line 180 that causes a "1" to be entered into the shift
register position 162-2. The high signal on the line 180 also sets
a flip flop 181 to the "1" state so as to enable an AND-gate 182.
If the correct pushbutton 161-7 next is depressed, a second input
is provided to the AND-gate 182 which in turn provides a high
output on a line 183 that enters a binary "1" into the register
position 162-7. The correct code now is contained in the shift
register 162.
The cooperation of the flip flops 178, 181 and the AND-gates 179,
182 insure that the pushbuttons 161-4, 161-2 and 161-7 must be
depressed in that order to accomplish correct code entry. An
appropriate mechanical or electrical interlock (known per se and
not shown) may be used to prevent code entry by simultaneous
depression of these three pushbuttons. The switches associated with
the remaining pushbuttons (e.g., the switches 160-1, 160-3, 160-5,
etc.) all are connected via a common line 185 to the reset input of
the shift register 162 and to the reset inputs of the flip flops
178 and 181. Thus if any of these incorrect pushbuttons are
depressed, the shift register 162 contents will be set to zero, and
the flip flops 178 and 181 will be reset so that correct code entry
is not accomplished. Of course, this pushbutton code selection
circuitry is illustrative only, and the invention is by no means
limited to the particular embodiment shown.
The pushbutton assembly 160 may be used solely to replace the
key-lock operated ignition switch 17 (FIG. 2), and not for entry of
the code transmitted to the receiver/decoder 25. To this end, a
ganged switch 187 is actuated so as to open the normally closed
contacts 187a and to close the normally open contacts 187b. As a
result, when the correct code has been entered into the shift
register 162, the high output of the comparator 163 on a line 165a
will be supplied via the closed switch 187b to a gate 188. This
gate 188 replaces the switch 17 (FIG. 2) and connects the voltage
from the battery 19 to the line 29a. The encoder/transmitter 23
then operates as described above to transmit the code stored in the
memory 31. This in turn is recognized by the receiver/decoder 25
and actuates the power switch 28. Of course, in this embodiment the
recognition code stored in the register 164 (FIG. 8) need not be
the same as that contained in the memory 31 and the storage
register 53, and preferably is different. To actuate the engine,
the user must select via the switches 160 that code which is stored
in the register 164. The signal on the line 165a from the
comparator 163 also is supplied via a delay circuit 169 to the
reset terminal of the shift register 162 so as to reset the
contents thereof to zero after correct code recognition has been
completed.
* * * * *